Snow tread



United States Patent O M 3,160,190 SNOW TREAD Daniel N. Jediny, 212Washington Ave., Garfield, NJ. Continuation of application Ser. No.156,320, Dec. 1, 1961. This application Jan. 15, 1963, Ser. No. 251,698Claims. (Cl. 152-209) This application is a continuation of myapplication Serial No. 156,320, led December 1, 1961 now abandoned, andrelates to snow treads for solid or pneumatic tires or for crawlerplates.

I provide by my invention a novel snow tread through which effectivetraction on snow or ice-covered ground is obtainable without sacrificeof smooth riding performance on clear road surface.

I contemplate a snow tread which during travel on snow or ice willdevelop from the snow or ice particles a tread-entrapped pattern ofperipheral -icy cleats for increasing traction, relying on the fact thatsnow or ice coheres with itself, by a process of fusion, more durablythan with any other substance.

My invention provides a snow tread in which the tread surface isinterrupted by la pattern of recesses or cells opening substantially atthe tread surface to induct snow or ice particles during travel on snowor ice-covered ground, each cell internally structured to entrap,retain, and mold the inducted frozen material into a compact, congealed,icy mass which, by reason of preferential adherence thereto of groundsnow or ice particles, will build up outwardly into an eifectivelyperipherally protrusive ice-like cleat lacting like a permanent cleat ofmetal or plastic but having the great advantage of disappearing upontransition of the tread toy a clear ground surface.

According to my invention, entrapment of the snow or ice particleswithin the tread cell is preferably effected by dimensioning the cellwith an internal girth exceeding the size of its intake opening, l mayprovide for Such relation between the internal girth of the cell and thesize of the opening by indenting or notching the side wall or walls ofthe cell but preferably I propose to are one or more of the sides of thecell toward the inner end, providing a cell having the shape of thefrustrum of a hollow cone or pyramid. Alternatively, my inventioncontemplates entrapment `of the snow or ice particles Within the cell bya supplemental trapping device inside the cell. Such trapping device maybe a porous, tined, or mesh structure. Each cell may be supplied withits individual trap, or a plurality of the cells may be respectivelysupplied with trap elements consisting of portions of a common web ornet, of wire or plastic, extending through solid tread rubber from onecell to =and across another. I further contemplate that both a largerinternal girth of cell and supplemental trapping means may be usedtogether for maximum entrapping effect on the snow or ice particlesinducted through the cell intake end.

My invention contemplates the use of either an unlined tread recess orcell or, for maximum traction on dense snow or ice, the lining orformation of the cell by metal or plastic material. Such lining may bealong one or more walls of the tread recess.

It is a characteristic of the cleat breeding recess or cell of my novelsnow tread that its side Wall or walls are to have effective rigidityfor maintaining the intake or outer end open under the weight of thevehicle equipped with the snow tread, whereby the intake end will beprepared to induct snow or ice particles during travel on snow orice-covered roads. The desired rigidity may be attained through use ofthe metal or plastic lining inside the recess or by proportioning therecess with a large intake opening relative to the depth of the recess.A preferred proportion is one in which the mean dimension of 3,160,190Patented Dec. 8, 1964 the intake opening is in the order of twice thedepth of the recess. This proportion provides the requisite rigidity andalso has the advantage of avoiding wedging and retention of stones,commonly spherical, inside the recess.

According to my invention, the inner or blind end of the cleat breedingrecess in my novel snow tread is provided with a projection pointingtoward the outer, open end and serving to divent and deflect inductedsnow or ice material toward the sides of the recess so as to facilitateand insure the molding of the material into the entrapping shape of therecess.

I contemplate that the cleat breeding recess may be disposedlongitudinally or transversely of the direction of tread travel or bothlongitudinally and transversely, as in the case of individual recesseswithin the tread.

According to my invention, each recess may have a separate lining or aplurality of the recesses may be formed around protruding cells of ametal or plastic web imbedded in the tread rubber, these cells thenserving as linings for the plurality of recesses.

Other objects and advantages of my invention will appear from thesubsequent description, the claims, and the drawings, wherein:

FIG. l is a vertical section through a portion of one form of my novelsnow tread, this portion being shown in riding traction on snow and withalready developed impermanent congealed snow cleats;

FIG. 2 is a detail section through an unlined cleat breeding recess ofconical frustrum shape;

FIG. 3 similarly shows a conieally lined cleat breeding recess or cell;

FIG. 4 is an outside, broken view of a fragment of the rim of a snowtread formed with an illustrative pattern of recesses at least some ofwhich are internally provided with snow entrapping meshes;

FIG. 5 is a section along line 5-5 of FIG. 4;

FIG. 6 is a section along line 6-6 of FIG. 5;

FIG. 7 is an outside, broken view of a small fragment of my novel snowtread with recesses formed around projecting cells of a web embedded inthe tread rubber; and

FIG. 8 is a section along lines 8-8 of FIG. 7.

Referring particularly to FIG. 1, the snow tire there indicated isprovided in its tread layer 10, of rubber, with one or morecircumferential arrangements of individual cleat breeding recesses 11.Each recess 11 is characterized by an internal girth greater than thearea of the open outer end, the shown recess having this characteristicby virtue of being shaped conically, as in FIG. 2, or pyramidally, as inFIG. 6, with its smaller end being the open end along the tread surfaceor plane. The side walls of the recesses have effective enough rigidityto maintain their outer open ends open under riding pressure. Suchrigidity is obtained for the shown recess by la recess depth in theorder of one-half the mean dimension of the outer open end. Thisproportion gives the necessary rigidity and also prevents stones fromlodging in the recess.

The convergence of the recess 11 toward the open end serves to entrapsnow or ice inducted into the recess. As the vehicle equipped with thesnow tread rides on a snowcovered road, `the ground snow is forced bythe Weight of the vehicle and load into the recesses meeting the snow.The snow forced into the recess is softened by the warmth of the treadand by the friction of compression and packs under pressure into adense, ice-like mass molded to the internal shape of the recess andsince this shape is convergent toward the periphery of the tread, theresulting molded icy slug is entrapped in the recess. In order to aidand insure the molding of the inducted frozen material to the shape ofthe recess, the inner end of the recess is formed with a projection 12pointing toward the intake opening and serving to divent ntruded snowtoward the side wall or walls of the recess.

When the icy slug entrapped in a recess 11 again meets the ground snow,its moist exposed end almost immediately unites or fuses with a quantityof the ground snow, a cohesive freezing between the exposed surface ofthe entrapped icy slug and the contacted snow taking place under ridingpressure and as the excess heat in the area of contact between the slugand the ground snow rapidly diifuses into the surrounding snow on theground. At this point, it may be noted that the cohesive force oradhesion between the snow and the exposed surface of the entrapped icyslug far exceeds the adhesion between the snow `and the tread rubberbetween recesses and is of considerably more durable nature. Theaccretion, by fusion, of ground snow to (the exposed end of theentrapped icy slug in the tread has the effect, in itself, of improvingtraction of the tread over the snow, since the accreted icy slug alreadybegins to act as a cleat. When the portion of the Itire with the icyslug turns up and away from the ground, a forcible separation of theslug together with its accreted quantity of snow takes place withrespect to the ground snow, and a next recessed portion of the tireturns into the snow.

Thus, during turning of the snow tire, each of the recesses 11 meets andpresses into the ground snow and inducts -a quantity of snow which moldsinto an icy slug entrapped in the recess. As the tread continues itstravel over the snow, each of 'the entrapped icy slugs grows outwardlyby successive accretions of ground snow over and around the exposed end,into an icy cleat designated C in FIG. 1. A pattern of ice-snow cleats Cthus is built up at spaced positions on the tire rim, by preferentialadherence or coherence of the ground snow with the entrapped icy slugsin -the recesses 11. These impermanent cleats C promote traction overthe snow-covered ground by reason of their cohesive action with theground snow and by reason of their penetration into the snow. The amountof snow accumulated on the entrapped icy slug in a recesses 11, or thesize of the protruding portion of the ice cleat C, depends on the numberand arrangement of the recesses and, also on the temperatures of theambient air, the tread and the ground snow, and on the density and depthof the ground snow.

When the tread and its developed pattern of cleats C encounter groundthinly covered by snow or ice, the cleats accumulate less and less ofthe snow or ice particles and diminish toward the plane of the tread.When the cleats have declined to the tread plane, there will still notbe a complete loss of cleat-like traction because the remnant icy slugscaptivated in the recesses 11 are relatively more rigid than the treadrubber and their outer edges will scrape any thin layers of ice or snowthey encounter, imparting a gear like traction eifect to the tire. Thescraped snow or ice particles also will serve to replenish the icy slugsand prevent their decline to less than eifective length.

When the tread passes from snow or ice covered ground to bare ground,the icy cleats C including the entrapped portions disappear by meltingaway due to the warmth of the tread generated by the riding friction.The tread then functions as a cleatless tread to provide smooth ridingtraction on the bare ground.

While the tread with unlined recesses functions effectively even ondense snow or ice, the lined recesses are preferred where dense snow orVice-covered roads prevail. This is because the more rigid liningmaterial will more eiectively scrape up dense snow or ice than theunlined recess.

The lining material may be metal or plastic. For the metal lining,spring metal or equivalent ilexible metal is preferred. Any suitable,hard, durable plastic, including hard rubber, may be used as liningmaterial. The lining may be single, separate units for the respectiverecesses or may be multiple units formed from a common web.

FIG. 3 shows an example of a unit-lined cleat breeding recess in thetread. In the shown example, the lining unit 13 is an inverted conicalfrustrum fitted snugly into the receptive cavity in the tread rubber.Projecting tines 13a anchor the lining securely in place. The outer edgeof fthe lining reaches substantially to the tread surface plane. Othershapes of lining may be used. For a pyramidal cavity, one or more of itsside Walls may be fitted with a lining. The blind or inner end of thecavity or the lining for the cavity will be formed with a projection 13bserving the same purpose as the projection 12 in recess 11 (FIG. 2).

The linings for a plurality of cavities in the tread may be connectedunits, as indicated in the example shown in FIGS. 7 and 8. Here a web15, either a continuous ring or a section of a ring and made of metal orplastic, is formed with projecting cells 15a. The cells may have anysuitable snow-ice entrapping shape, pyramidal, conical, or theequivalent. As shown, the cells are open-ended conical frustrums. In themanufacture of the tire, the web 15 and cells 15a become imbedded in thetread rubber to the level of the outer, smaller ends of the cells.Provision is made for blocking both ends of the cells against intrusionof rubber except for a projecting intrusion 16 having the same purposeas projection 12 (FIG. 1) or projection 13b (FIG. 3).

When the snow tread formed with the lined cavities tnavels on relativelysoft snow, the form-ation of icy cleats takes place the same as for asnow tread formed with unlined cavities. When the snow tread with linedcavities travels on packed or dense snow or ice, the sharp andunyielding outer edges of the linings scrape up packed snow or iceparticles which accumulate in the lined cavities, condensing therein toform icy slugs molded to the entrapping shape of the lined cavities. Bythe same process described before, the icy slugs unite at their outer,exposed ends with further scraped up snow or ice particles and build upto protruding ice-like cleats which reach slightly beyond the treadsurface. The size of the proltruding portion of the cleat is not asmassive as When the cleat builds up from soft snow, for the reason thatan ice-covered pavement or a pavement coated by densely packed snowpresents an extremely hard surface. The entrapped cleats, thoughsmaller, still serve through their cohesive coaction with the groundsnow or ice, to provide improved, gear-like traction on the snow orice-covered pavement.

Instead of relying on the shape of the cavity to retain the snow-icemass which builds up into a cleat, -a trapping element may be usedwithin the cavity. The trapping element may be individual to a cavity ormay be a part of a trapping web extending through the tread rubber intoa plurality of the cavities. As illustrated in FIGS. 4 and 5, a trappingweb 17 is moulded within the tread body and reaches across longitudinalgrooves 18 and individual, pyramidal recesses 19. The trapping web is ofmetal or plastic and may be a perforated web or a wire-mesh, as shown.The plane of the trapping element within a cavity is closer to the innerend of the cavity than to its outer, tread surface end, a small spacebeing preserved between the trapping element and Ithe inner end of thecavity to enable snow or ice particles to pack solidly on both sides ofthe trapping element. The trapping membrane or mesh should be exibleenough to prevent its being permanently crushed inwardly to the bottomof the cavity when the tire rolls over pebbles and small stones. Snowinducted in the cavi-ty 18 or 19 during travel on a snow-covered roadcondenses on both sides of the wire mesh yand clings thereto, forming anucleus for any icy slug which takes the shape of the cavity.

Entrapment of the snow in a cavity 19 is not only effected by the wiremesh but by the convergence toward the outer end of a pair of oppositeside walls of the cavity, indicated in FIG. 6.

Also shown in FIGS. 4 and 5 is a longitudinal cleat breeding recess 20which entraps snow by convergence 0f the side walls toward the outer,open end. The recess 20 is formed Iat the bottom with a longitudinal ribor projection 21 for deflecting the inducted snow-ice mass to the sidesof the recess, insuring the molding of the inducted mass to theentrapping shape of the recess. Similarly, the recesses 18 and 19 alsomay be provided with projections for the same purpose.

To prevent the congealed mass or cleat ice trapped in rthe longitudinalrecess from slipping around the tire, the recess is interrupted atintervals along the length by cross pieces such as the cross piece 22integral with the tread lrubber.

While the invention has been disclosed in connection with particularembodiments, it is understood that variations may be made withoutdeparting from the principle of the invention; therefore, I intend to belimited only as indicated by the following claims.

What is claimed is:

1. A snow tread for traction on snow or ice-covered ground as well :ason bare ground surface, said tread being characterized by a recess openat its outer end along the tread surface to induct snow or ice materialduring travel of the tread on snow or ice-covered ground, said recessbeing internally structured to entrap the inducted snow or ice materialas a congealed, icy slug for uniting at its exposed end with furtherencountered ground snow or ice material to develop into an icytraction-promoting cleat.

2. The invention as defined in claim 1, the entrapping structure of therecess comprising a lateral wall structure of greater girth than thearea of the snow inducting end.

3. The invention ias dened in claim 1, the entrapping structure of therecess comprising an inwardly ared lateral wall structure.

4. The invention as delined in claim 1, the entrapping structure of therecess being constituted by a pyramidal lateral wall structureconverging toward the open outer end of the recess.

5. The invention as defined in claim l, the entrapping structure of therecess being constituted by a conical lateral wall structure convergingtoward the open outer end of the recess.

6. The invention as defined in claim l, said recess having aneffectively rigid side wall structure for maintaining the outer end ofthe recess open under riding pressure.

7. The invention as dened in claim l, said recess being provided with aprojection pointing from the inner, blind end of the recess toward theouter end to deect the inducted snow to the side of the recess andinsure molding of the inducted mass to the internal shape of the recess.

8. The invention as dened in claim 1, said recess being lined withmaterial of greater rigidity than the tread material.

9. The invention as deiined in claim 1, said recess being providedinternally with a t-ted individual lining of material more rigid thanthe -tread material.

10. The invention according to claim l, the tread being formed with aplurality of individual recesses and a plurality of connected relativelyrigid cells imbedded in the tread material and around which theindividual recesses are formed, the cells serving as linings for saidrecesses.

11. The invention according to claim l, the snow tread being providedwith a pattern of such recesses including a recess extendinglongitudinally along the tread rim.

12. The invention according to claim 1, the entrapping structurecomprising a supplemental snow-ice trap element across the recess.

13. The invention according to claim l2, said trap element being Iaporous membrance crossing the recess be- -tween its inner and outerends.

14. The invention according to claim 13, said membrane being a Wiremesh.

15. The invention according to claim 14, said wire mesh being a sectionof a web of wire mesh imbedded in the tread and extending therethrough:across a plurality of said recesses.

References Cited in the file of this patent UNITED STATES PATENTS952,014 Morris Mar. 15. 1910 1,105,880 Cooper Aug. 4, 1914 2,424,647Bernkull July 29, 1947 2,575,439 Billingsley Nov. 20, 1951 FOREIGNPATENTS 798,397 France Mar. 10, 1936 1,163,341 France Apr. 21, 1958

1. A SNOW TREAD FOR TRACTION ON SNOW OR ICE-COVERED GROUND AS WELL AS ONBARE GROUND SURFACE, SAID TREAD BEING CHARACTERIZED BY A RECESS OPEN ATITS OUTER END ALONG THE TREAD SURFACE TO INDUCT SNOW OR ICE MATERIALDURING TRAVEL OF THE TREAD ON SNOW OR ICE-COVERED GROUND, SAID RECESSBEING INTERNALLY STRUCTURED TO ENTRAP THE INDUCTED SNOW OF ICE MATERIALAS A CONGEALED, ICY SLUG FOR UNITING AT ITS EXPOSED END WITH FURTHERENCOUNTERED GROUND SNOW OR ICE MATERIAL TO DEVELOP INTO AN ICYTRACTION-PROMOTING CLEAT.